title: Differential neural mechanisms underlying exogenous attention to peripheral and central distracters.
abstract: Mechanisms underlying exogenous attention to central and peripheral distracters were temporally and spatially explored while 30 participants performed a digit categorization task. Neural (event-related potentials-ERPs-, analyzed both at the scalp and at the voxel level) and behavioral indices of exogenous attention were analyzed. Distracters were either biologically salient or neutral, in order to test whether the exogenous attention bias to the former observed in previous studies is independent of, or interacts with, distracter eccentricity. Two subcomponents of the N2 component of the ERPs, N2olp and N2ft, reflected processes related to peripheral distracters processing. N2olp effects, located in the dorsal attention network (supplementary motor area), were probably related to covert reorientation to peripheral distracters. N2ft effects, located in the default mode network (posterior cingulate cortex), appeared to reflect less effort in the ongoing task when peripheral distracters were presented. N2ft also showed a biological saliency effect which was independent of eccentricity and was located in the polar/ventral prefrontal cortex. P3 showed greater amplitudes to centrally presented distracters. These latter effects were located in TEO (visual cortex), and would be functionally associated with spatial interference between the target and central distracters. Behavior showed the relevance of both central and peripheral distracters in exogenous attention. These results indicate that exogenous attention to peripheral distracters differed in temporal and spatial terms from exogenous attention to central distracters and that it is biased towards biologically salient events irrespective of their eccentricity.
authors.affiliation: Facultad de Psicología, Universidad Autónoma de Madrid, 28049 Madrid, Spain. carretie@uam.es
authors.forename: Luis
authors.initials: L
authors.lastname: Carretié
authors.forename: Jacobo
authors.initials: J
authors.lastname: Albert
authors.forename: Sara
authors.initials: S
authors.lastname: López-Martín
authors.forename: Sandra
authors.initials: S
authors.lastname: Hoyos
authors.forename: Dominique
authors.initials: D
authors.lastname: Kessel
authors.forename: Manuel
authors.initials: M
authors.lastname: Tapia
authors.forename: Almudena
authors.initials: A
authors.lastname: Capilla
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D015982:Bias; D001921:Brain; D001931:Brain Mapping; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D025341:Principal Component Analysis; D011930:Reaction Time; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Biological saliency; Default mode network; Distracter eccentricity; Dorsal attention network; N2/P3; Ventral/polar cortex